side effects, adverse drug reactions and toxicity

Question 1

Side effects

Answer 1

Consequence of pharmacological mechanism of action of the drug
Usually due to the presence of multiple receptors in a number of tissues or lack of receptor specificity
*cannot completely eliminate side effects

Question 2

Adverse drug reaction

Answer 2

Any response to a drug that is harmful and unintended that occurs at doses normally used in humans
e.g. severe tachycardia or tremor in a pt who has had a normal dose of salbutamol

Question 3

Type A ADR

Answer 3

Common
Predictable based on drug MOA
Dose-dependent
Low morbidity and mortality
*Majority of ADRs

Question 4

Type B ADR

Answer 4

Uncommon 
Unpredictable 
Not dose dependent or based on MOA
High mortality rate
Due to individual factors (genetic, host, hypersensitivity)
Addressed by discontinuation

Question 5

Risk factors for ADRs

Answer 5

Age, disease state, gender, genetics/ethnicity, immunological factors, number of drugs

Question 6

Drug risk factors for ADRs

Answer 6

Narrow therapeutic index
Route of administration
Formulation/bioavailability
Additive/excipients

Question 7

Identifying of ADRs

Answer 7

Accurate drug hx + medial hx

Dechallenge and rechallenge

Question 8

Poisoning

Answer 8

Due to toxic effects (overdosage) of drugs
Children at high risk
Combination or ER formulations make tx difficult

Question 9

Treatment of poisoning

Answer 9

Maintain ventilation/BP
Reduce absorption
Increase elimination
Ensure hydration and electrolyte balance

Question 10

Paracetamol poisoning

Answer 10

Undegoes phase II metabolism (conjugation) to inactive forms
Conjugation capacity is exceeded - paracetamol then metabolised by CYP2E1 to a toxic metabolite - NAPQI